Individual answerer answering time interval recording system for a teaching machine

ABSTRACT

An individual answerer answering time interval recording system for a group response device utilized, for instance, in a teaching machine for a large number of pupils, wherein the time interval from the instant a question is given to a number of pupils to the instant a selected percentage of the pupils answer the question is measured, timing pulses based on the said time interval and having a recurrence period in proportion thereto are produced and are counted successively, and each time a new answer occurs, the counted number of the said pulses is stored in a memory zone of a buffer memory for said answerer. Thus, the system records the answer time of each pupil in terms of the percentile group of its occurrence, rather than in terms of fixed units of time, e.g. pupil A answered question 1 within the time of the first 5% of all answers, student B answered the question within the time of the last 5% of all answers, etc.

United States Patent Yamauchi INDIVIDUAL ANSWERER ANSWERING TIMEINTERVAL RECORDING SYSTEM FOR A TEACHING MACHINE Inventor:

Foreign Application Priority Data Jan. 11, 1973 Japan 48-6124 US. Cl.35/8 R; 35/9 R; 35/48 R Int. Cl. G09B 7/00 Field of Search 35/8 R, 8 A,9 R, 9 A,

35/9 B, 22, 48 R, 48 B; 235/184; 340/324 R References Cited UNITEDSTATES PATENTS lllllillil Primary Examiner-Robert W. Michell AssistantExaminer-Vance Y. Hum

Attorney, Agent, or Firm-Cooper, Dunham, Clark, Griffin & Moran 1ABSTRACT An individual answerer answering time interval recording systemfor a group response device utilized, for instance, in a teachingmachine for a large number of pupils, wherein the time interval from theinstant a question is given to a number of pupils to the instant aselected percentage of the pupils answer the question is measured,timing pulses based on the said time interval and having a recurrenceperiod in proportion thereto are produced and are counted successively,and each time a new answer occurs, the counted number of the said pulsesis stored in a memory zone of a buffer memory for said answerer. Thus,the system records the answer time of each pupil in terms of thepercentile group of its occurrence, rather than in terms of fixed unitsof time, eg pupil A answered question 1 within the time of the first 5%of all answers, student B answered the question within the time of thelast 5% of all answers, etc.

4 Claims, 6 Drawing Figures Sheet 1 of 5 3,911,596

mwhzmzoo U.S. Patent 0a. 14, 1975 N QE US. Patent Oct. 14, 1975 FIG. 4

Sheet 3 0f 5 BUFFER 7 REGISTER Ge-l US. Patent Oct. 14, 1975 Sheet 5 of53,911,596

REGISTER Q5} H BUFFER G2 RREC WER

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MONOSTABLE MULTIVIBRATOR INDIVIDUAL ANSWERER ANSWERING TIME INTERVALRECORDING SYSTEM FOR A TEACHING MACHINE BACKGROUND AND SUMMARY OF THEINVENTION This invention relates to an answering time interval memorysystem, and more particularly to an individual answerer answering timeinterval recording system for a group response device used, forinstance, in teaching machines for a large number of pupils.

Recently, teaching machine systems for use by a large numberof pupilshave been adopted. In these teaching machines, the time interval fromthe instant a question is given to the pupils to the instant the answeris obtained (answering time interval) is converted to a digital code andis stored on a recording medium such as magnetic tape, paper tape or thelike. Subsequently, the recorded data is read out for various types oftotalling, analysis, etc. In this connection, the time interval from theinstant a question is given to pupils to the instant the answer isobtained is not constant but varies substantially with the degree ofdifficulty of the question, the knowledge of the pupils, etc. And, ifthis substantially varying time interval is converted directly to adigital code, the corresponding number of bits may on occasion be verylarge, not only causing the required recording space of the recordingmedium to be increased but also making subsequent data handlingextremely complicated. To solve this problem, it is possible to neglectanswering time intervals which exceed a certain limit. However, withthis method, it is impossible to ensure correct control over thelearning process.

The object of this invention is to provide an individual answereranswering time interval recording system fora group response devicewhich permits recording of the answering time interval of each pupil,which interval may vary substantially with the degree of difficulty ofthe question or the background of the pupil, on a recording mediumwithout excessively increasing the number of bits required.

In more detail, an object of this invention is to provide an individualanswerer answering time interval recording system for a group responsedevice such that the answering time interval of each pupil is stored ina buffer register, the form of a time factor based on a time scale thtvaries in accordance with the distribution of all answer times to aquestion. Subsequently, the stored data is read out and recorded on arecording medium such as magnetic tape, paper tape or the like.

According to one embodiment of this invention, the time interval 1' fromthe instant a question is given to a number of pupils to the instant thepercentage answering reaches, for instance, 5% is digitally measured andset in a register. The content of the register is compared with theconte'nt of a first counter which is advanced with clock pulses having adefinite recurrence period, and if coincidence exists a timing pulse issent out. At the same time, the content of the said first counter iscleared, and subsequently, again it is advanced with the clock pulse. Inthis way, if the content of the first counter coincides with the contentof the said register, again the timing pulse is sent out. Subsequently,the afore-mentioned operation is repeated, and a second counter isadvanced with the said timing pulseUAdditionally, a buffer memory havinga plural number of memory zones each of which corresponds to each pupilby one-to-one correspondence is provided. And, each time a new answeroccurs, the counted value of the said second counter at that time isstored in the memory zone corresponding to the answerer in the buffermemory. In short, the counted value of the said second counterrepresents the time factor of the true answering time interval, and saidtime factor is stored in place of the true answering time interval inthe buffer memory. Subsequently, the content ofthe buffer memory isrecorded on a recording medium such as magnetic tape, paper tape or thelike and can be utilized for various further processing. Thus, the timeeach student takes to answer a question is measured and recorded not astrue time, but as time along a normalized time scale.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph which shows atypical distribution of the answer times for a question which is givento a large number of pupils,

FIG. 2 shows an example ofa prior art circuit for generating a timescale signal which reflects the distribution of answer times,

FIG. 3 shows an embodiment of the individual answerer answering timeinterval recording system ,according to this invention,

FIG. 4 shows a modification of the system of FIG. 3,

FIG. 5 shows another embodiment of a system according to this invention,and

FIG. 6 is a modification of the system of FIG. 5.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring to FIG. 1, a graph showsa typical answer rate curve, Le, a plot of the time from the posing of aquestion to a number of pupils versus the percentage of the pupils whohave answered the question. In the figure, the abscissa shows the time,and the ordinate shows the percentage answering, where the percentageanswering is defined as follows.

number Of ZIIISWEZI'CI'S number of total pupils Percentage answering IFrom FIG. I, it is seen that typically the percentage of pupils who haveanswered the question is very small, in general, during a certain timeinterval from the instant the question is given (this time interval isdenoted by 1' in the figure), and after the time interval of 1-,increases exponentially until settling at a predetermined value after atime interval, for instance, of 31-. The time interval of r largelyvaries with the degree of the difficulty of the question or knowledge ofthe pupil. Likewise, the slope of the curve after the time interval of'r is closely related to 7. That is, if r is large, the curve is flat,while if r is small, the curve is steep. In the following, the timeinterval of'r will be assumed to be the time interval within which 5% ofthe students answer the question, although it is of course not necessarythat the value should be 5%. In FIG. 1, a unit time interval of l whichshows one scale division of the time axis is defined based on the timeinterval of 'r assumed above (i.e. t is a defined submultiple of 7). Itis easy to understand that the unit time interval of t varies with 'r.The answering time interval of a pupil can be denoted by T a1 (2) wherea is the time factor defining the answer time of that student on anormalized time scale. According to this invention, this time factor aof each pupil is obtained based on the said time interval of -r and itis utilized in place of the actual answering time interval.

FIG. 2 shows a prior art (see US. Pat. No. 3,8l8,483) circuit forgenerating timing pulses having a recurrence period corresponding to theunit time interval of t mentioned above. Referring to FIG. 2, A- counter1 is a binary counter to count a first pulse train P B-counter 2 isanother binary counter to count a second pulse train P Start signal P,,takes a high level at the instant a question is given to the pupils.Stop signal P, takes a high level at the instant the percentage of thepupils that have answered the question reaches That is, the timeinterval from the instant the start signal P, takes the high level tothe instant the stop signal P, takes the high level corresponds to thetime interval of 1' described with reference to FIG. 1. When the startsignal P takes the high level, flip-flop 5 is set. The set output offlip-flop 5 is supplied to AND gate 6. Therefore, when the flip-flop 5is set, the first pulse train P is passed through AND gate 6 to theA-counter 1 where it is counted. Subsequently, the pupils start toanswer, and when the percentage answering reaches 5%, the flip-flop 5 isreset with the stop signal P,. Then, the A-counter 1 stops counting andcontains a value corresponding to the time interval of 'r.

The reset output of the flip-flop 5 is supplied to AND gate 7. When theflip-flop 5 is reset, the second pulse train P is passed through the ANDgate 7 to the B- counter 2 where it is counted. When the counted valueof the B-counter 2 coincides with the content of the A- counter 1,coicidence circuit 3 sends a coincidence output and this output drivesmono-stable multivibrator 4. P, is the output pulse from the mono-stablemultivibrator. The B-counter 2 is cleared by the pulse P Subsequently,when the pulse P,. disappears, the B- counter 2 starts counting againand its content is compared with the content of the A-counter l.Subsequently, the operation mentioned above is repeated to send out thepulse P having a predetermined recurrence period successively from themonostable multivibrator 4.

Now, let the recurrence periods of the first pulse train P and secondpulse train P be T and T respectively, and assume the following relationbetween them.

T n'Tz where n is an integer. Let the counted value of the A- counter 1be n,, then the time interval of -r is T mT Substituting Eq. (3) in Eq.(4) gives Further, if we let the counted value of the B-counter 2 be nthen the period T, of pulse P, is given by the following formula.

z' z Therefore, from Eq. (5) and Eq. (6),

When the counted values of both counters l and 2 coincide with eachother, n, n and Eq. (7) becomes as follows.

Eq. (8) means that the recurrence period of pulse P, varies with 1'. Asa result, by scaling of the time axis with the pulse P,., it is possibleto display or record a curve as shown in FIG. I in a definite spaceirrespective of the length of the response time. Such a system hasalready been proposed by the inventor of this invention. For the detailsof this system, refer to US. Pat. No. 3,818,483 issued on June 18, 1974.

FIG. 3 shows a block diagram for an embodiment of this invention.Referring to FIG. 3, correct answerer register 10 is a shift registerhaving the capacity of series bits of the number equal to the number ofpupils questioned. Each bit position in this shift register is allocatedfor each pupil. In the group response device in which the correctanswerer register is adopted, a group of slave units arranged at thepupil stations is scanned at a fast speed by means of clock pulseshaving a suitable recurrence period and at the same time, the correctanswerer register is shifted in synchronism with the same clock pulse.Each correct answer or wrong answer of each pupil found by the scanningof each slave unit is set as l or 0 respectively at each bit positionallocated for each pupil in the correct answerer register. Such a groupresponse device has already been proposed by the inventor of thisinvention. For the details, refer to US Pat. application No. 291,620filed on Sept. 25, 1972. The I or 0 state set in the correct answererregister 10 is displayed on a display unit 11 having display elementscorresponding to bit positions of the register 10. Block 12 is a timeaxis timing pulse generator constructed as shown in FIG. 2. Block 13 isa binary-coded decimal counter (time scale counter) to count the timingpulse P, sent from the pulse generator 12. It is easy to understand thatthe counted value of counter 13 shows the time factor a based on thetime interval of 1' described with reference to FIG. 1. Take for examplethe case where, as shown, the counter 13 is of 5-bit configuration andits bit positions are decimal weighted I, 2, 4, 8 and 10. Blocks 14, 14are a group of buffer registers comprising shift registers of the numberequal to the number of bits of the counter 13. Each buffer register hasthe same bit capacity as the correct answerer register 10 and its eachbit position is allocated for each pupil by one-to-one correspondence asin the correct answerer register 10. The group of buffer registers l4 14is shifted in synchronism with the clock pulse (not shown) given to thecorrect answerer register 10.

Normally, gates G -l G -5 are in the on-state and gates G -l G 5 are inthe off-state. In this condition, the content of each of bufferregisters l4 14 is simply re-circulating in synchronism with the clockpulse. During this period, each time each slave unit arranged at eachpupil station is scanned, the answering condition of each pupil at thattime is supplied as a series pulse train of I and 0 through input lineto the correct answerer register 10 to renew the content of the register10.

Take for example the case where the first pupil makes a correct answerand the bit corresponding to the first pupil in the pulse train giventhrough the input line 1 to the register 10 is changed from 0 to Whenthe l signal showing the correct answering of the first pupil is appliedon the input line the 0 signal for the same first pupil already set inthe correct answerer register 10 is given to inversion circuit N insynchronism therewith. Then the gate G is turned on by the 1" signalfrom the input line I, and inversion circuit N so that 1 signal is givenon the line 1 As the result, gates G -I G -5 are turned off and gatesGg'l G -5' are turned on so that the buffer registers l4 14 stopre-circulation for one clock pulse and the counted value of the counter13 is stored in parallel at the bit positions corresponding to the firstpupil in buffer registers 14, 14 That is, the counted value of thecounter 13 showing the time factor a of the first pupil is stored at thepositions corresponding to that first pupil in the buffer register 14 14Similarly, when any pupil gives makes a correct answer, then lines 1 and1 are turned to l at the scanning time corresponding to the pupil andthe counted value of the counter 13 is stored at the bit positionscorresponding to the pupil in the buffer registers l4 14 Subsequently,each time the pulse train of 1 and show- 1 ing the correctanswering-wrong answeringcondition of each pupil is given on the inputline the operation mentioned above is repeated so that at each bitposition in the buffer registers 14 14 the time interval (accurately thetime factor a of the time interval of 7) required for the pupilcorresponding to the said position to make a correct answer is stored asthe counted value of the counter 13. Of course, bit positionscorresponding to those pupils who make no answer and wrong answer arekept in the 0 state. The content of the buffer registers 14, 14 issubsequently read out in parallel and is recorded on a recording mediumsuch as magnetic tape, punch tape or the like (not shown). If at thesame time a value showing, for instance, the time interval of r isrecorded on the recording medium, it will be convenient for latercalculating the true response time of each pupil. For this value of 'r,the content of the counter 1 shown in FIG. 2 may be used. That is, sincethe counted value of the counter 1 represents the value of r, it may berecorded on the recording medium.

In the circuit configuration shown in FIG. 3, an inconvenience willoccur as follows. If a pupil, once making a correct answer, makes awrong answer by redepressing an answer button (not shown) on the slaveunit at the pupil station, the response time interval which is at thattime stored for the previous correct answer in the buffer registors 1414 This inconvenience can be eliminated by changing the circuitconfiguration to that shown in FIG. 4.

Referring to FIG. 4, where those parts identical to FIG. 3 are shown byidentical symbols, and only one of the buffer registers 14 14 that is,register 14, is shown, the operation of this circuit is as follows. If apupil, once making a correct answer, makes a wrong answer byre-depressing an answer button, then 0" signal appears on the input lineI and as the result, AND gates G G -l and G -l are turned off so thatthe buffer register l4 stops circulation of its content. Then, becausethe signal on the line 1 is 0 and the output of the correct answererregister is I AND gate G is turned on. Therefore, if, for instance, onthe line a specific code signal showing non-correct answering has beengiven, the said code signal is passed through AND gate G -1 and ON gateG -l and is stored at the bit position corresponding to the pupil whomade the said wrong answer in the buffer register 14,. The line is theoutput line for the first bit of the counter 13 shown in FIG. 3.

In the circuit configuration shown in FIG. 3, each 6 time a new answererprovides a correct answer, the counted value of the time factor counter13 at that time is stored at the bit positions corresponding to the saidcorrect answerer in the buffer registers. The storing of said countedvalue in the buffer registers in this may be done each time the timingpulse P,. which advances the time factor counter is generated. Thecircuit configuration to this end is shown in FIG. 5. It differs fromFIG. 3 in that between the correct answerer l0 and the buffer registers14,- 14 a new correct answerer is register having the same bit capacityand the content of the'said register 15 isoutputed as the new correctanswerer information only when the monostable multivibrator.l6 driven bythe timing pulse P operates.

- In the steady state, AND gates G and G -l G -5 are in the on-st-ateand AND gates G and 0 -1 G -5 are in the offstate so that the contentsof the new correct answerer register 15 and buffer registers 14, 14 aremerely circulating. Each time a new correct answerer is entered throughthe input line I, in the. correct answerer register 10, AND gate G isturned on and the said new correct answerer is entered in the register15. That is, the bit position corresponding to the pupil who makes a newcorrect answer in the register 15 is set to I Then, upon arrival of thetiming pulse P the time factor counter 13 is advanced, and at the sametime, the monostable multivibrator 16 operates to turn on the AND gate6,, for a time period of one circulating cycle of each register so thatthe new correct answerer information is outputted successively from theregister 15 through the gate 9 to the line 1 As the result, the countedvalue of the counter 13 is entered at the bit positions corresponding tothe new correct answerer in the buffer registers 14,- 14 This operationis the same as in FIG. 3. During this period, the AND gate G is in theoff-state so that the new correct answerer register 15 stops circulationand the content is cleared. Subsequently, each time the timing pulse P,is generated, the operation mentioned above is repeated and the countedvalue of the counter 13 at that time is entered at the predeterminedpositions in the buffer registers l4 14 In this circuit configuration,the function to invert the new correct answerer information on the line1 is accomplished by a single inversion circuit N but, of course, it ispossible to provide a separate invertor for each buffer register asshown in FIG. 3. Even if a new correct answer occurs during the periodfor which the monostable multivibrator 16 is in operation, there is noinconvenience because it is passed through gates G and G and entered inthe new correct answerer register 15. FIG. 6 shows a re-depressinganswerer register 17 having the same bit capacity as the new correctanswerer register 15 so that the circuit configuration of FIG. 5 has thesame function as described in FIG. 4.

The foregoing refers to the embodiments of the invention where the timeinterval (on a normatized time scale) from the instant a question isgiven to the instant a correct answer is made by the pupil is recorded.Of course, it is possible to similarly record any answer irrespective ofwhether it is correct or wrong.

What is claimed is:

l. A teaching system having a plurality of pupil stations, each stationhaving means for providing an answer signal indicating the answer of thepupil to a question posed to the plurality of pupils, said systemfurther having means for determining which answer signals representcorrect answers and which represent wrong answers, and comprising:

means for determining a selected percentage of the pupil stationsproviding a defined answer signal;

means for determining the duration of the time interval from the posingof a question to the pupils until a selected percentage of the pupilstations have provided a defined answer signal; means for generating asuccession of time scale signals at a rate corresponding to the durationof said time interval; v means for counting the number of said timescale sig nals from a time corresponding to the posing of the question;and means for storing,- for each pupil station, an answer time signalrepresenting the number counted by the counting means at a timecorresponding to the time the pupil station providesa correct answersignal, thereby providing an indication of the time each pupil has takento answer the question as related to the time it has taken to receiveanswers from a selected percentage of the pupils. 2. A teaching systemas in claim 1 including means for deleting the stored answer time signalfor a pupil station which provides a wrong answer signal subsequent tohaving provided a correct answer signal.

3. A teaching system as in claim 1 wherein the counting means providesas an output a multibit number representing its contents and wherein thestoring means comprises a buffer register for each bit of the countingmeans output, each register having a bit position corresponding to eachpupil, the multibit number at the output of the counting means beingstored in the bit positions of said buffer registers corresponding tothe pupil station which has provided a correct answer signal.

4. A teaching system as in claim 3 including a correct answer registerhaving a bit position corresponding to each; pupil station, the contentsof each bit position being changed from one binary state to another whenthe corresponding pupil station provides a correct answer signal, thestoring of the counter means output in the corresponding bit positionsof the buffer registers occurring at the time of changingthe contents ofthe corresponding bit position in the correct answer register.

l l l

1. A teaching system having a plurality of pupil stations, each stationhaving means for providing an answer signal indicating the answer of thepupil to a question posed to the plurality of pupils, said systemfurther having means for determining which answer signals representcorrect answers and which represent wrOng answers, and comprising: meansfor determining a selected percentage of the pupil stations providing adefined answer signal; means for determining the duration of the timeinterval from the posing of a question to the pupils until a selectedpercentage of the pupil stations have provided a defined answer signal;means for generating a succession of time scale signals at a ratecorresponding to the duration of said time interval; means for countingthe number of said time scale signals from a time corresponding to theposing of the question; and means for storing, for each pupil station,an answer time signal representing the number counted by the countingmeans at a time corresponding to the time the pupil station provides acorrect answer signal, thereby providing an indication of the time eachpupil has taken to answer the question as related to the time it hastaken to receive answers from a selected percentage of the pupils.
 2. Ateaching system as in claim 1 including means for deleting the storedanswer time signal for a pupil station which provides a wrong answersignal subsequent to having provided a correct answer signal.
 3. Ateaching system as in claim 1 wherein the counting means provides as anoutput a multibit number representing its contents and wherein thestoring means comprises a buffer register for each bit of the countingmeans output, each register having a bit position corresponding to eachpupil, the multibit number at the output of the counting means beingstored in the bit positions of said buffer registers corresponding tothe pupil station which has provided a correct answer signal.
 4. Ateaching system as in claim 3 including a correct answer register havinga bit position corresponding to each pupil station, the contents of eachbit position being changed from one binary state to another when thecorresponding pupil station provides a correct answer signal, thestoring of the counter means output in the corresponding bit positionsof the buffer registers occurring at the time of changing the contentsof the corresponding bit position in the correct answer register.